User's Manual
Table Of Contents
- 1 Overview
- 2 GE864-QUAD V2 Mechanical Dimensions
- 3 GE864-QUAD V2 module connections
- 4 Hardware Commands
- 5 Power Supply
- 6 Antenna
- 7 Logic level specifications
- 8 Serial Ports
- 9 Audio Section Overview
- 10 General Purpose I/O
- 10.1 GPIO Logic levels
- 10.2 Using a GPIO Pad as INPUT
- 10.3 Using a GPIO Pad as OUTPUT
- 10.4 Using the RF Transmission Control GPIO4
- 10.5 Using the RFTXMON Output GPIO5
- 10.6 Using the Alarm Output GPIO6
- 10.7 Using the Buzzer Output GPIO7
- 10.8 Indication of network service availability
- 10.9 RTC Bypass out
- 10.10 External SIM Holder Implementation
- 11 DAC and ADC section
- 12 Conformity Assessment Issues
- 14 Document Change Log
GE864-QUAD V2 Hardware User Guide
1vv0300841 Rev.0.1 24/11/09
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 39 of 65
NOTE: The UART input line TXD (rx_uart) of the GE864-QUAD V2 is NOT internally pulled up with a resistor, so
there may be the need to place an external 47KΩ pull-up resistor, either the DTR (dtr_uart) and RTS (rts_uart) input
lines are not pulled up internally, so an external pull-up resistor of 47KΩ may be required.
A power source of the internal interface voltage corresponding to the 2.8VCMOS high level is
available at the PWRMON pin on the connector, whose absolute maximum output current is 1mA.
A maximum of 9 resistors of 47 KΩ pull-up can be connected to the PWRMON pin, provided no other
devices are connected to it and the pulled-up lines are GE864-QUAD V2 input lines connected to
open collector outputs in order to avoid latch-up problems on the GE864-QUAD V2.
Care must be taken to avoid latch-up on the GE864-QUAD V2 and the use of this output line to power
electronic devices shall be avoided, especially for devices that generate spikes and noise such as
switching level translators, micro controllers, failure in any of these condition can severely compromise
the GE864-QUAD V2 functionality.
NOTE: The input lines working at 2.8VCMOS can be pulled-up with 47KΩ resistors that can be connected directly to
the PWRMON line provided they are connected as in this example.
NO OTHER devices than those suggested should be powered with the PWRMON line; otherwise the module
functionality may be compromised.
It is important to consider that the added circuit must have consumption lower than 1mA.
In case of reprogramming of the module has to be considered the use of the RESET line to start correctly the
activity.
The preferable configuration is having an external supply for the buffer.